Opponents of France’s proposed Marriage for All law granting same-sex couples marriage and adoption rights staged an impressive show of force Jan. 13 by mobilizing up to 800,000 marchers against the measure. But while ruling Socialists responded to the self-described Protest for All with vows to pass the legislation when it goes before Parliament Jan. 29, the size of the demonstration served to illustrate significant divisions within France toward the initiative. Those clashing positions also exist within otherwise united political camps — including what some observers claim is the ambivalent attitude of French Socialist President François Hollande.

Sunday’s Paris marches attracted what organizers said were 800,000 very boisterous protesters. Police estimates put those numbers closer to 340,000, though even that more than tripled the 70,000 to 100,000 who participated in an earlier demonstration in November. General momentum around Marriage for All appears to be similarly shifting. A recent opinion poll found 56% of French people backing the legalization of gay marriage — about 10 points lower than levels in November 2012. The same survey found support of adoption rights for gay couples dropping four points to 45%. Despite those evolving views, the ruling Socialists responded to Sunday’s protest by vowing to pass their Marriage for All law for the country’s own good.

“The government is totally determined to realize this reform — this historic advance that isn’t a victory of one camp over another, but progress for all of society,” said government spokeswoman and Women’s Rights Minister Najat Vallaud-Belkacem on Europe 1 radio Monday. “We’re taking note of this [demonstration] … [But] it’s before Parliament that this issue will be debated, not in the streets.”

Yet to a considerable degree, that debate is already raging in protest corteges and public meetings across France, where political conservatives, religious leaders and their followers — and even some leftists who all feel the stability of the family is being undermined by the draft law — are voicing their opposition to it. In an effort to undercut anticipated criticism that their position is built on mere homophobia, detractors of Marriage for All are focusing their message on defending the traditional family unit and protecting children.

Defenders of the initiative, meantime, are swapping their initial confidence (and possible complacency) about the law’s passage with energetic counterdemonstrations supporting the measure. An initial Paris march on Dec. 16 attracted between 60,000 and 200,000 people, and a follow-up rally is planned for Jan. 27. Supporters call the legislation another step toward reversing long-standing discrimination of gays by granting them the same marriage and adoption rights that heterosexual couples enjoy; they also say Marriage for All will broaden and strengthen families, not destroy them.

Those contrasting positions have thus far prevented debate over the draft law from becoming a shouting match pitting incompatible camps of religious fundamentalists and traditionalists against the gay community and social progressives. Given the multiplicity of groups on both sides of the debate, stereotyping either camp is almost impossible.

In fact, divisions over the legislation even cuts within party ranks. Jean-François Copé, leader of France’s main conservative Union for a Popular Movement (UMP) party, participated in Sunday’s march to represent official UMP hostility to Marriage for All. However, several party figures — including members of former President Nicolas Sarkozy’s cabinet — have come out in strong support of the measure, and even criticized conservatives blocking what they say is an important advance many other European countries have already embraced.

Meanwhile, extreme-right National Front (FN) leader Marine Le Pen refused to demonstrate Sunday alongside conservative foes like Copé whom she accuses of politically “exploiting” opposition to the measure — in contrast to the FN’s heartfelt rejection of it. Yet some pundits suspect it was actually Le Pen’s personal views on gay issues — which have at times been more tolerant than the official FN line and also more liberal than that of some mainstream conservatives — that motivated her absence Sunday.

There’s even been speculation that Hollande himself is of mixed minds on the Marriage for All legislation. In his private life Hollande has fathered four children and had long, stable relationships with at least two women — including current partner and First Lady Valérie Trierweiler — without ever seeing the utility of marriage along the way. For that reason, some French observers suspect Hollande supports Marriage for All more out of progressive ideology and political symbolism than from reverence of matrimony as an institution everyone should be getting in on.

There have been other hints of Hollande’s hesitancy. As the text of the legislation slowly made its way toward Parliament, Hollande dismayed some fellow leftists by refusing calls to add an amendment granting same-sex couples access to state-subsidized medical assistance in conceiving children. He also set off a tempest by suggesting French mayors who personally oppose Marriage for All on ethical grounds could cite “freedom of conscience” in refusing to conduct civil ceremonies in same-sex marriages.

Government officials have repeatedly rejected Hollande’s purported ambivalence, assuring skeptics that the President is fully behind the measure. Be that as it may, that determination won’t likely alter what seems to be the emphatically conflicting attitudes in wider France on same-sex marriage and adoption — nor squelch loud opposition to Marriage for All, even after it’s the law of the land.